Multi piece filter for smoking device

ABSTRACT

A multi-piece filter assembly for use in a smoking device such as a cigarette, cigarette holder or the like in order to filter out tars and other harmful products from the smoke emanating from burning tobacco, comprising a primary filter and a secondary filter, with the primary filter including a member containing two or more minute holes, with the smoke passing through these minute holes being caused to increase in velocity as a result of the small size of the holes, and therafter decrease in velocity, with this decrease in velocity causing a depositing out of the tars and related undesirable substances. Various arrangements are provided for disposing the primary filter disk in the desired relationship to the tobacco of the smoking device, and may include the use of a generally cylindrical supporting means that tends to heat up during use as the smoke passes through, with such heating causing an enhancement of the filtering action.

United States Patent [1 1 Wright [451 Sept. 18, 1973 i 1 MULTI-PIECE FILTER FOR SMOKING DEVICE [76] Inventor: Marjorie E. Wright, 929 Greentree Dr., Winter Park, Fla. 32789 [22] Filed: Jan. 21, 1970 [21] Appl. No.: 4,717

Related U.S. Application Data [63] Continuation-in-part of Ser. No. 593,876, Nov. 14,

1966, abandoned.

2,954,782 10/1960 Lebert.. 131/201 X 1,594,606 8/1926 Clivio.... 131/201 X 3,373,750 3/1968 Beam l31/10.5 3,351,072 11/1967 Baum et al.... 131/l0.7 X 2,954,783 10/1960 Lebert 131/201 X 2,762,375 9/1956 Fessler 131/194 Primary Examiner-Robert W. Michell Assistant ExaminerJohn F. Pitrelli Attorney.lulian C. Renfro [57] ABSTRACT A multi-piece filter assembly for use in a smoking device such as a cigarette, cigarette holder or the like in order to filter out tars and other harmful products from the smoke emanating from burning tobacco, comprising a primary filter and a secondary filter, with the primary filter including a member containing two or more minute holes, with the smoke passing through these minute holes being caused to increase in velocity as a result of the small size of the holes, and therafter decrease in velocity, with this decrease in velocity causing a depositing out of the tars and related undesirable substances. Various arrangements are provided for disposing the primary filter disk in the desired relationship to the tobacco of the smoking device, and may include the use of a generally cylindrical supporting means that tends to heat up during use as the smoke passes through, with such heating causing an enhancement of the filtering action.

1 Claim, 14 Drawing Figures PATENTEB SEPI 8M3 SHEET 1 BF 3 I N VEN TOR. Mame/5 E. WE/Gl/T PATENTEDSEPIGIBB 3.759.270

' I NVEN TOR. MEJOE/EE WE/Gx/f PATENTEDSEFWIBH 3.759.270

SHEET 3 0F 3 I INVENTOR MPJOE/E 5 49 9 ATTORNEY MULTI-PIECE FILTER FOR SMOKING DEVICE An invention of Marjorie E. Wright, 929 Greentree Dr., Winter Park, Fla., 32789, which is a Continuation in Part of her application Ser. No. 593,876, filed Nov. 14, 1966, now abandoned.

This invention relates to an improved, inexpensive yet effective filter for removing tars and other undesirable substances from tobacco smoke, which filter is extremely versatile in its utilization, enabling it to be used in cigarette holders and pipes, and being even inexpensive enough for direct use in cigarettes.

In the past, a number of types of filter arrangements have been proposed for removing undesirable substances from tobacco smoke and a number of these are in use today. At the present time, when many people are quite conscious of the medical warnings associated with the use of tobacco, at least 65 percent of the cigarettes sold to the public are equipped with filter tips, which tips have achieved some success in the removal of tars.

Cost is an important item that must not be overlooked in the design of cigarette filters, for while the purchaser expects to pay something extra for filter tip cigarettes, he or she cannot be expected to pay an amount that would represent more for the filter than for the tobacco.

Probably the most popular type of filter tips are those made of cellulose in various forms and many smokers are comforted by the fact that in use the filter tip takes on a brown color, for this is indicative to the smoker that his or her lungs have been spared that much tar. This is to a large extent misplaced confidence, for it is a proven fact that still a sizable percentage of the nicotine and tars come through to the smoker despite whether the cellulose type filter is used alone, or in conjunction with conventional items such as charcoal, moistened cotton or other such arrangements.

Certain filters are now on the market that operate on a substantially different principle, these being devices used in cigarette holders, in which a tiny elongated passage is defined through which the smoke is drawn. Because of the small size, the smoke is drawn through the passage at very high speed by the user's efforts, with the smoke at the discharge end of the passage being directed at a barrier upon which the tar-bearing smoke impinges. However, the high velocity of the smoke stream is apt to create a faster burning cigarette, and some tar-like substances still escape. A device of this type, being more complicated in construction, is not nearly as economical, especially in cigarettes, as my less expensive filter of similar or higher efficiency.

A multi-piece filter assembly in accordance with this invention is a combination type device in that it utilizes a primary filter and a secondary filter, with the primary filter utilizing a member having at least two tiny holes through which the smoke must pass. A generally cylindrical supporting means may be utilized for supporting the member in the desired filtering position. This supporting means can either have straight sides or slightly conical sides, with both ends open. The filter member may be held in the correct filtering position by the use of an inturned flange or rim in the downstream end of the supporting member, or alternatively the filter disk may be disposed on the outside of this supporting member and secured to such rim or inturned member by non-toxic glue, cement or the like so that a tight seal is effected. I have found it preferable to use absorbtive paper in the construction of the filter member, and this paper can even be ofa type to produce a precipitation of the tars and solids out of the smoke because of a degree of acidity of the paper. The holes in the filter disk can be the size of a small needle or the like, with the number of holes being from say two to six. A pressed charcoal disk may be used if preferred to paper. I have also found it highly advantageous to have the supporting member made of aluminum or other material tending to heat up in use, as the smoke from the burning tobacco passes through, for this heating of the supporting member brings about an enhancement of the filtering action.

As to the secondary or final filter, this may be a more or less conventional filter of paper, cellulose, or pressed charcoal with minute holes, its chief purpose being to slow down the smoke velocity, allowing it time to swirl and cool and cause a more complete combustion of the burning tobacco, and in the case of the pressed charcoal disk, to further cool and purify the ensuing gases. In all embodiments, the secondary filter is more porous than the primary filter.

As will be apparent, this unique and highly advantageous design may be utilized in a number of different ways. For example, my novel filter assembly may be used in a cigarette, cigarette holder, or even in a cigar holder or a pipe. The filter assembly may be of inexpensive enough construction as to be expended as a part of the cigarette butt, or re-used in a holder with several successive cigarettes or cigars for example. In a holder it is constructed to be easily replaceable.

The generally cylindrical supporting means and the filter member contained therein or thereon form an integral unit that can be removed as a unit from the holder or cigarette, and replaced as a unit, or alternatively only the member or disk representing the primary filter need be frequently replaced. Small tabs or the like on this disk or member may make it possible to remove it easily from the supporting means so that a new one may be placed in its stead.

A narrow band of filter material may also be preformed as a truncated cone with the heat holding qualities to hold the paper or plastic filter disk disposed in its end, or conversely, the disk may be applied to the outer edge of the cone end in many ways, including a type of strip-tape with minute spaced holes throughout, the strip-tape being of at least the diameter of the small end of the truncated cone.

My invention may utilize as its filter members a pair of essentially parallel disks disposed between a filter tip and a narrow band of filter adjacent the tobacco, the narrow band of filter being used to prevent tobacco from blocking the holes. These disks are each equipped with at least two needle size holes preferably disposed in a non-aligned arrangement, through which holes all of the smoke being inhaled by. the user must pass. Because the smoke must attain very high speed in passing through these holes, and because of a chamber thus defined between the disks, the heavier components of the smoke are caused to deposit out, partly as a crystalline formation on the back sides of the holes, and partly in small formations on the downstream filter member in .alignment with the holes of the upstream disk.

the fact that smoke must not be allowed to escape around the outer periphery of the initial filter member, that is, without going through the minute holes. This is of course prevented by constructing the disks or other such members to fit closely in the encircling wrapper of the cigarette, or in the cigarette or cigar holder, or in the pipe stem as the case may be.

The shape of the chamber or cavity defined between the filter means can vary in accordance with the different elements used, and as a matter of fact the filter members can be disks as previously mentioned, or alternatively may be in the form of caps, cones, capsule ends or the like, so long as the support means is ofa different material than the respective filter member, and so long as the stream of smoke can pass through small holes in the filter member into and out of the chamber defined by these components.

It is therefore a principal object of my invention to provide an efficient, low cost filter for use with tobacco products, utilizing at least one component having minute holes therein, which holes serve to speed up the stream and deposit out heavier tars, and a second component for further slowing down the smoke stream, for a causing a further depositing out of the tars, and for assuring more complete combustion in the cigarette.

These and other objects, features and advantages will be apparent from a study of the drawings wherein:

FIG. 1 shows in an exploded, perspective type view a filter type cigarette utilizing a multi-piece filter involving a pair of caps or filter members held by supporting means in spaced relation, each member equipped with minute openings that are effective for removing a large quantity of the tars contained in burning tobacco;

FIG. 2 is a perspective view similar to FIG. 1 but differing in showing a different facing of the caps, that is, with the rims of the filter members facing together so as to define and determine the space between their active surfaces;

FIG. 3 is a view similar to H68. 1 and 2 except that the tar trap is composed of a cap and cone arrangement with the minute openings of the cone disposed on the upper slanted sides of the cone;

FIG. 3a is another view of the multi-piece filter assembly of FIG. 3, but taken from another perspective;

FIG. 4 is an illustration of the use of multiple tar traps employed in series;

FIG. 5 is a tar trap in which my novel multi-piece filter disks or filter members are mounted in a tubular member having sufficient body that it can receive in one end thereof, the tip of a cigarette, even a cigarette manufactured with a conventional filter tip, thus assuring the smoker that as much filtering action as is reasonably possible is being carried out;

FIG. 6 is a throw away filter usable in a cigarette holder and consisting of an outer cone type member in which are mounted filter caps equipped with minute out of alignment holes, with the holes in the cap nearest the mouthpiece being slanted toward the inside of the cone so that tars can deposit thereon, with the upstream edge of the cone member having means for easy removal from the holder;

FIGS. 7a and 712 show other arrangements of the use of cone-shaped filter members in which minute, out of alignment holes are provided through which smoke is drawn by the smoker;

FIGS. 8a and 8b reveal various arrangements of capsule type filter parts, also equipped with minute holes;

FIG. 9 shows a preferred form of my invention, using a primary and secondary filter, in this instance these being disposed in a cigarette holder containing in one end thereof an aluminum cone of a size to receive the tip of a cigarette, with one filter disk or member disposed in the bottom of the cone, and a second disk spaced close by;

FIG. represents a slightly different preferred embodiment of a multi-piece filter assembly, in which the secondary filter is in the form of packed cellulose; and

FIG. Ml shows a cylindrically shaped tar trap device in accordance with this invention utilized for a pipe, with the arrangement being such that when the stem of the pipe is removed from the bowl portion, one end of the cylindrically shaped member can be easily grasped for removal and replacement.

Turning first to FIG. 1 it will be noted that a novel cigarette filter in accordance with one embodiment of my invention is shown in exploded relation, with the outer wrapper 1G opened to reveal the novel tar trap ill, the first filter 12 used to prevent clogging of the trap with tobacco, and the tobacco portion 13. The first filter can take the form of any of a number of devices, such as for example of cellulose, open weave cloth or the like. A final filter 14 is disposed between the tar trap 11 and the end of the cigarette placed in the mouth. Filter M may also be of cellulose.

In this embodiment, the filter members constituting the tar trap 11 are a pair of substantially flat primary and secondary members 15 and 16, made of paper, plastic, or even of pressed charcoal. These members or disks are mounted approximately ,41 to A inch apart in spaced parallel relation for easy assembling, with holes 37 and id therein.

Furthermore, the filter disks should be secured in airtight relation with respect to the outer wrap of the cigarette, and to that end in this embodiment I prefer the use of a band 19 that is sealed tightly about the circumferential or flange portions of the disks or filter members so as to define an airtight unit. The tar trap 11 is of course disposed between cellulose filter portions 12 and 14% before the outer wrap ltl) is applied about the tobacco and the various filter components to define the cigarette. Preferably, the outer wrap is closely sealed to the outer portion of band 19 to prevent smoke passing between these components.

As a result of this construction, upon the smoker drawing directly upon the final filter 14, smoke from the ignited tobacco is caused to flow through the initial filter 32, through the tar trap 11 in accordance with this embodiment, and thereafter through the final filter. It should be noted that as a result of the presence of band 19, the smoke cannot undesirably circumvent the filter disks 15 and to, but rather must find its way through the needle size pairs of holes 17 and 13.

The smoke passing through the minute holes 37 of the upstream or primary disk 15 increases in velocity, and then thereafter decreases in velocity, thus causing a change such that the tars and related substances deposit out. This initial filter desirably has fewer holes than the second filter, which second filter primarily is used to slow down the smoke stream.

Turning to FIG. 2 it will be noted that the tar trap 21 there defined utilizes disks 25 and 26 much like those of tar trap it, except that the flange or rim portions of disks 25 and as are turned so as to face toward each other, thus to define the distance the perforated portions of the filter disks are spaced apart. Holes 27 are disposed in primary member 25, and holes 28 are located in secondary member 26.

As will therefore be seen, the smoke that is caused to travel through the tobacco 23 travels through initial filter 22, thence through tar trap 21, and thereafter through final filter 24 into the mouth of the smoker. It should be noted that the tar trap 21 can be manufactured as a separate entity by securing the wrapper band 29 about the peripheries of disks 2S and 26 before the outer wrap is applied about the end of the cigarette, including the two filter members 22 and 24.

The holes l7, 18 in the disks of FIG. l, and the holes 27, 28 in the disks of FIG. 2 are preferably of the order of magnitude of 0.017 inch in diameter, which of course means that each hole has an area of approximately 0.000289 square inches. The material constituting the disks is preferably of a thickness of say 0.0045 to 0.006 inch, but of course I am not to be limited to these figures. Preferably, the disks have absorbent or adsorbent qualities inasmuch as this enhances the tar holding ability of the disks.

Turning now to FIG. 3 and related FIG. 3a, it will be noted that the smoke after flowing through initial filter 32 thereafter flows through the first member 35 of the tar trap, and more particularly flows through the slanted holes 37 that may be disposed at spaced locations about member 35. As will be noted, member 35 is generally in the configuration of a hollow truncated cone, with the holes 37 being disposed therein at an angle, which has the effect of defining a slightly more tortuous path for the smoke before it endeavors to flow through holes 38 of the adjacent disk 36. This arrangement has the effect of causing part of the deposits of tar to be absorbed by the sides of the trap, that is, the wrapping sealer 39. In this embodiment the paper from which the wrapping sealer is constructed may desirably be of a particularly absorbent or adsorbent type.

The particular relationship of members 35 and 36 may be more apparent from fragmentary FIG. 3a, wherein the interior or primary filter member 35 is depicted. The central or filtering portion may be of paper, and the outer or peripheral portion of material that tends to heat up in use. The use of band 39 about members 35 and 36 causes a tar trap 31 of integral construction to be defined, through the holes 37 and 38 of which all the smoke from the burning tobacco 33 passes.

Turning now to FIG. 4, it will be noted that this figure shows a multiple arrangement of tar traps, the disks 45a and 46a being of course upstream members, and the disks 45b and 46b being the downstream members. The disks 45a and 45b therefore define a tar trap through which all the smoke from burning tobacco 43 must pass before entering the downstream tar trap with which it is in series. In this embodiment, as in the previous embodiments, the holes or perforations in the disks may be out of alignment, thus amounting to a deliberately tortuous path that causes as much tar as possible to be deposited out before the smoke is drawn through the final filter 44.

FIG. 5 shows the use of stationing means for locating the perforate filter disks 55 and 56. In this instance, the member 50 may be made either of relatively heavy paper, cork, plastic or the like, with circumferential slots provided therein to receive the filter disks 55 and 56.

Member 50 may be formed by rolling, with these various components placed in position before the edges or ends of the rolled material are secured together. This construction may be utilized integrally with the tobacco 53 so as to define a cigarette or cigar with an expendable filter, or alternatively, the member 50 may be deliberately constructed so that the tip end of a cigarette (even a filter cigarette) can be inserted therein, adjacent recessed initial filter 52. In this arrangement as before, the smoke is caused to travel through the holes in primary member 55 and secondary member 56 so as to define an arrangement in which the tars and other undesirable substances are caused to deposit out.

FIG. 6 reveals a holder 60 designed to receive either a cigarette or a cigar, this member being constructed preferably of plastic. An elongated conical member 66a in which spaced perforate disks and 66 are mounted fits into the tapered end of member 60, with the tip of this conical member being open at a location adjacent mouthpiece 64.

The cone 66a is preferably made of absorbent type paper and can extend slightly beyond the rim edge for easy removal from the cigarette holder. Alternatively, small pull tabs may be utilized for helping to disengage the filter member from the holder so that it and its con- 'tents may be discarded preparatory to inserting a new filter cone.

Slanted holes are preferably used in the embodiment in accordance with FIG. 6 so as to direct deleterious substances against the upper slanted sides of the paper cone for the purpose of absorption.

FIG. 7a shows to a somewhat smaller scale another arrangement of disk and cone, these members 73 and 74 being almost opposite to the arrangement shown in FIg. 3 in that the smoke is first drawn through the minute holes of the disk, and thereafter into the cone as a restraining member of a different shape. The primary member 73 involves as previously explained and described, an outer supporting member and an inner filter member, with the holes in the filter member arranged so that the smoke travels somewhat outwardly, toward the cone I sides. The holes in cone 74 are likewise slanted so that the smoke travels outwardly, thus to cause the tars and other deleterious substances to deposit on the inner portion of the cylindrically shaped outer member.

In FIG. 7b, the members 75 and 76 are in the form of cones that are separated somewhat from a nested position. The holes in the filter member of primary filter 75 are arranged so as to bring about a deposition of tars on the interior of secondary member 76, preferably toward the apex portion of 76. At this point the smoke turns and travels radially outwardly and rearwardly toward the holes of member 76, thus to define a very effective trap for tars. Further, the holes in 76 are slanted outwardly so as to cause a depositing of tars on the interior of the outer wrap. In both of these figures, each of the filters preferably involves an outer, supportive structure, and an inner portion or member that serves as a filter.

FIG. 8a shows an embodiment in which the filter members are neither flat nor pointed. In this instance, primary and secondary filters 83 and 84 are each of capsule" shape that are interlocked to prevent the flow of smoke except through the holes, and so that only the rim edge of a sturdier material of member 83 need be sealed to the inner surface of the cigarette filter wrapper. The mid portion of member 83 performs the principal filter action.

In FIG. 8b the capsule-shaped members are of equal outer diameter so that the wrapper used to make a common unit of these members can be easily sealed to each. Preferably the holes of both of these units are slanted somewhat outwardly.

FIGS. 9 and Qa represent a preferred type of construction for a filter in accordance with my invention. In both of these figures, a multi-part filter arrangement is utilized, involving a combination filter and a restraining filter.

In FIG. 9, the combination filter involves a primary member or disk 97 mounted upon a generally tubular supporting means in the form of a member 95 whose sidewalls may be straight, or slanted such that a form of truncated cone is created. Thus, the primary filter member is held in an effective filtering position, in this instance adjacent the forward end of a cigarette holder 96. The disk 97 is equipped with from two to six or more minute holes, through which all the smoke from the burning tobacco must pass. Although various alternatives are possible within the spirit of my invention, I prefer that the bottom or smaller end of the generally tubular supporting means 95 be equipped with an inturned edge or flange, with of course the major portion of the bottom of member 95 being left open. The disk 97 (or disk 97a of FIG. 9a) is preferably inserted inside the member 95 to such a degree that it resides tightly against this inturned edge or flange, with this edge or flange preventing the disk 9'7 or 97a from being inserted too far. Alternatively, the disk 97 or 97 a may be secured with non-toxic glue or cement, or other suitable means to the outer portion of this edge or flange. The disks of course are of a different material than the supporting member, and are preferably of paper or plastic.

Used in conjunction with the primary disk 97 in FIG. 9 is a secondary filter member, this being in the form of a disk 95, that typically has two or more small holes through which all the smoke must pass. It is desirable to have a slightly larger number of holes in the secondary filter than in the primary filter, or slightly larger holes.

In operation, the generally cylindrical supporting member 95 tends to heat up slightly as smoke from the burning tobacco is caused to pass through, and this has a salutary effect upon the filtering process. That is, I have found that when the member 95 tends to heat during its use, the filtering effect brought about by the primary filter member 97 (or 97a) is enhanced.

The secondary filter member is not as important for filter purposes as is the primary filter, and its size and shape may vary. The secondary filter serves the purpose of slowing down the combustion process of the cigarette, and this slowing down of the burning rate can be accomplished by the use of a member 93 having small holes. Alternatively, and as seen in FIG 9a, the secondary filter member 99 may be a moderately hard packed piece of cellulose, which can be sealed somewhat so as to decrease its porosity, yet still allowing for a satisfactory draw.

For example, the member 99 could even be in the nature of cleansing tissue or the like, that is disposed close by so as to receive a deposit of tar. The amount of air flow must be controlled so that too much air does not flow through the second member, this of course being controlled by the packing of the member 99. As is expected, the surface of member 99 nearest the disk 97a tends to accumulate a deposit of tar, particularly at locations in alignment with the holes of disk 970. It should be remembered that in use, the aluminum member tends to heat up somewhat, and this tends to enhance the buildup of tarlike deposits on the downstream member.

The advantages of the described arrangements of FIGS. 9 and 9a are several. For one, the supporting member 95 may be made of a sturdy material, for example a light metal, such as aluminum, which is of course a good conductor of heat, and which rapidly tends to heat up as the smoke from the burning tobacco passes therethrough. If this combination filter is to be used in a cigarette holder, the aluminum member may remain in position, and only the filter member 97 or 97a removed as may become necessary during use. For example, small tabs may be provided to enable the filter member to be removed easily. The disks may also be sold separately at drug counters or at tobacco stores so that replacement can be effected as necessary or desirable. Alternatively, of course, the entire combination filter 95, 97 may be discarded and replaced by a new unit.

As to the construction of the disk 97 (97a), I prefer an absorbtive type of paper in which tiny. holes have been pricked or otherwise disposed. Another alternative is plastic which in some ways is less effective than paper, but in other ways is better, such as the fact that the holes do not tend to close up during use, and likewise can give the desired quick-cooling effect. The plastic members can be used either as disks, or suitable plastic could be sprayed on the supporting means and thereafter pricked with a needle point at several locations to form the minute holes. Pressed charcoal may be another alternative for the primary filter member or the secondary filter member, or both, in which members tiny holes have been located.

In FIGS. 9 and 9a, the primary filter member and the secondary filter member may be separated entities disposed in a holder for a cigar or cigarette, or may be overwrapped in approximately the position shown in FIG. @a with paper or the like, so as to form an entire filter assembly.

Also with regard to FIGS. 9 and 9a, it must be borne in mind tht this preferred form of the invention is not to be limited to use in a cigar holder or cigerette holder, for it obviously could be manufactured into a cigarette or cigar as an intrinsic part thereof.

The holes in the primary filter members 97 and 97a are preferably of the order of magnitude of 0.017 inch in diameter, which of course means that each hole has an area of approximately 0.000289 square inches. The material constituting the disks is preferably of a thickness of say 0.0045 to 0.006 inch, but of course I am not to be limited to these figures.

Turning now to FIG. 10, a pipe is depicted comprising a bowl member 103, and a stem 104. The juncture of these members is recessed to receive a cylindrically shaped container member 100 in which one or two pairs of perforate disks in accordance with my invention are mounted. In the preferred embodiment shown, the upstream disk members Elisa and 1051: form one filter trap, and the members 1060 and 106i? form the other trap. The member 100 is easily removed for replacement purposes upon the stem being removed from the pipe.

As will now be seen, I have provided a low cost yet highly effective trap for removing tars and other carcinogenic substances from tobacco smoke, involving the use of a spaced pair of filter members having minute holes through which the smoke is drawn. The inletoutlet relationships are such that a type of trap and constraining chamber are formed by these members, which literally traps the heavier components of the smoke, causing a depositing out of tars and related substances on the downstream member as well as in the passage downstream of the two filter members. Advantageously the smoker can still enjoy an easy draw, but the tortuous passage provided as a result of the holes in the pair of filters causes fluctuations in the speed of the smoke passing through the tar trap, thus bringing about an extensive depositing out of the tars and other harmful substances. 1 have found that the deposited tars often have a dull, paraffin-like lustre, with the deposits on the downstream side of the minute holes often possessing definite peaked" configurations in some instances, and crystalline type deposits in other instances.

Cost is obviously a factor to be considered, particularly in instances of direct use of my invention in the tips of cigarettes, so paper is the preferred material from which the filter members are made. The paper should have some rigidity as well as being somewhat absorbent, but should not be too porous. In some instances the members have been made of sandpaper, which tends to increase the amount of tar buildup around the minute holes. However, I am not to be limited to paper, for as mentioned before, components of plastic, pressed charcoal or other materials could be used if preferred.

1 have found that the upstream member is the more important of the two filter members, and preferably contains two to six mintue, needle size holes. The configuration of the chamber defined between the first and second filter members is not critical, as is to be seen from the fact that many different arrangements of filter members may be used. However, it is important for the second or downstream filter member to have the right relationship to the first member insofar as flow is concemed, and if properly paired, these members will define a trap that will remove far more tars from tobacco smoke than is possible with ordinary filters on the market today. The tightness with which the tobacco in a cigarette is packed will influence its draw, and obviously more porosity in some instances and less porosity in other instances will be necessary insofar as trap components are concerned in order that an optimum filtering action will be created. Porosity can of course be controlled by regulating the number of holes used in the filter members.

Normally, most of the tars are trapped between the first and second filter members, and this is of particular advantage when my invention is used in cigar and cigarette holders. or in pipes, for this means that less cleaning of the holder or pipe stem is necessary.

The word tar or tars as used herein is intended to relate to deleterious and carciogenic type substances, often showing in the deposits as reddish to dark brown colorations.

As should now be apparent, l have described a number of embodiments of my multi-piece filter assembly for use in a smoking device such as a cigarette, cigarette holder or the like in order to effectively and economically filter out tars and other harmful products from the smoke emanating from burning tobacco. In each of these embodiments l have shown and described a primary filter involving a comparatively sturdy supporting means and a filter member held in the filtering position by the supporting means, with the supporting means and its filter member being regardable as an integral unit, but whose components are nevertheless made of different materials. The primary filter may be arranged to be replaceable as an integral unit when used in a cigar holder or cigarette holder, or alternatively, the filter member only may be replaced, and the supporting means used over and over.

In all of these embodiments, the filter member of the primary filter is provided with a number of minute holes, such as of 0.017 inch in diameter, preferably formed in comparatively thin paper or plastic of a thickness of say 0.0045 to 0.006 inch. Absorbtive or adsorbtive paper may be used as the filter member of the primary (or secondary) filter, or plastic molded to the supporting member or separate therefrom may be used if preferred. The secondary filter utilized downstream of the primary filter in all embodiments is more porous than the primary filter members, for this arrangement l have found makes the primary filter more efficient.

I claim:

1. A mouthpiece and filter assembly for use in conjunction with a cigarette or the like comprising: a holder having an upstream end for receiving a cigarette and a downstream end for insertion into the mouth of a user, said holder having a passage therein being slightly decreasingly tapered from said upstream end to said downstream end; a metallic, tubular, substantially frusto-conically shaped member removably inserted in said upstream end of said holder, said member having an inturned flange at its small end and a cigarette receiving opening'in its large end; a first filter means comprising a planar paper disk plurality a plurzlity of minute holes in the plane of the disk, said disk being positioned against said inturned flange and extending across the smoke conducting passage of said tubular member, said paper disk being readily removable from said tubular member, and a second tapered filter means comprising a porous, absorbent plug conforming to the tapered passage of said holder thereby blocking the smoke conducting passage of said holder, said second filter means being spaced from said paper disk in a downstream direction and being more porous than said first filter means. 

1. A mouthpiece and filter assembly for use in conjunction with a cigarette or the like comprising: a holder having an upstream end for receiving a cigarette and a downstream end for insertion into the mouth of a user, said holder having a passage therein being slightly decreasingly tapered from said upstream end to said downstream end; a metallic, tubular, substantially frustoconically shaped member removably inserted in said upstream end of said holder, said member having an inturned flange at its small end and a cigarette receiving opening in its large end; a first filter means comprising a planar paper disk having a plurality of minute holes in the plane of the disk, said disk being positioned against said inturned flange and extending across the smoke conducting passage of said tubular member, said paper disk being readily removable from said tubular member, and a second tapered filter means comprising a porous, absorbent plug conforming to the tapered passage of said holder thereby blocking the smoke conducting passage of said holder, said second filter means being spaced from said paper disk in a downstream direction and being more porous than said first filter means. 